Referring to FIG. 1, a conventional curtain assembly 1 includes a fixing unit 11, a curtain 12, a plurality of rods 13, a plurality of rings 14 and a cord unit 15. The fixing unit 11 includes a cord guiding member (not shown). The curtain 12 has a lower end 121, an upper end 122 opposite to the lower end 121 in a vertical direction (V), a plurality of retaining portions 123, and a plurality of middle portions 124. The upper end 122 is connected to the fixing unit 11. The retaining portions 123 are formed by sewing, are arranged between the lower and upper ends 121, 122 in the vertical direction (V), and are connected to the middle portions 124. Each of the rods 13 is inserted in a respective one of the retaining portions 123 of the curtain 12. Each of the rings 14 is connected to a corresponding one of the retaining portions 123. The lowest one of the middle portions 124 is disposed between the lower end 121 and the lowest one of the retaining portions 123. The highest one of the middle portions 124 is disposed between the fixing unit 11 and the highest one of the retaining portions 123. The remaining middle portions 124 are disposed between corresponding two of the retaining portions 123. Each of the middle portions 124 has opposite lower and upper segments in the vertical direction (V). The cord unit 15 has two first cord portions 151, and a second cord portion 152 that is connected to the cord guiding member of the fixing unit 11. Each of the first cord portions 151 of the cord unit 15 interconnects the lower end 121 of the curtain 12 and the cord guiding member of the fixing unit 11, and extends through corresponding ones of the rings 14.
The second cord portion 152 of the cord unit 15 is operable to raise or lower the curtain 12. When the second cord portion 152 is operated to raise the curtain 12, the first cord portions 151 are gradually wound on the cord guiding member of the fixing unit 11 at the same moment that the lower end 121 is pulled toward the upper end 122 of the curtain 12. When the lower segment of each of the middle portions 124 is raised to reach the position where the adjacent one of the rods 13 is located, a folded part 125 of the middle portion 124 is defined.
When wishing to change the vertical length of the folded part 125 of the curtain 12, the curtain assembly 1 would have to be redesigned and remade to have different numbers of the retaining portions 123, resulting in higher manufacturing costs.